A Straight Spline Ring Gauge is a precision measuring tool used to inspect the accuracy of external splines on shafts or other components. It functions as a "go-no-go" gauge, verifying the effective tooth thickness, form diameter, and overall conformance to dimensional specifications. This ensures proper fit and interchangeability of splined parts.

Checking Effective Tooth Thickness: They verify the actual size of the spline teeth, ensuring they are within the specified limits.
Form Diameter Verification: The gauges also check the overall diameter of the spline, ensuring it is within the required tolerances.